Coal-exit Alliance Must Confront Freeriding Sectors to Propel Paris-aligned Momentum

The global phase-out of coal by mid-century is considered vital to the Paris Agreement to limit warming well-below 2 °C above pre-industrial levels. Since the inception of the Powering Past Coal Alliance (PPCA) at COP23, political ambitions to accelerate the decline of coal have mounted to become the foremost priority at COP26. However, mitigation research lacks the tools to assess whether this bottom-up momentum can self-propagate toward Paris alignment. Here, we introduce dynamic policy evaluation (DPE), an evidence-based approach for emulating real-world policy-making. Given empirical relationships established between energy-economic developments and policy adoption, we endogenize national political decision-making into the integrated assessment model REMIND via multistage feedback loops with a probabilistic coalition accession model. DPE finds global PPCA participation <5% likely against a current policies backdrop and, counterintuitively, foresees that intracoalition leakage risks may severely compromise sector-specific, demand-side action. DPE further enables policies to interact endogenously, demonstrated here by the PPCA’s path-dependence to COVID-19 recovery investments. Coal phase-out is an irreplaceable part of the overall mitigation effort and bottom-up momentum has emerged to accelerate the process. With a new approach considering political feasibility, this research shows the potential spillover risks that may undermine the sectoral actions.